Due to some emails I've received on this issue.

Players who finish in the Top 30 of the ATP World Tour Year-End Rankings are required to play four ATP World Tour 500 level tournaments the following year (Side Note: one of these 500 level tournaments must be played after the US Open). So, as a top 30 finisher in the ATP Rankings in 2009, Rafa was required to play four ATP 500s in 2010. However, since Rafa played only two 500s in 2010, he received two “Zero-pointer” penalties - which were assigned to the last two 500s of the year where he chose not to play (Valencia & Washington).
These Zero-point penalties stay on a player’s ranking for 52 weeks. Rafa's Barcelona points will therefore not count towards his ranking until the next Zero-Point penalty falls off. This will be on August 8th, 2011 when his Zero-Pointer penalty for Washington is removed and his 500 points from Barcelona will take its place.


Points gained from each tournament played last year remain on a player's rankings list for 52 weeks (1 year) counting from the first Monday after each tournament is finished, irrespective of any possible changes in the calendar this year as it has happened this year with the switch between Madrid and Rome.

After the 52th week expires, the points are dropped.

The additional complication are point penalties (zero pointers) for failing to play the required number of certain tournaments, but again both dropping and adding of points follow the same 52-week pattern.

Also, switching of points between tournaments can happen, simply because of the rule that only the highest score among the required tournaments is considered.
 

New rankings are up.
I hardly post the rankings unless something out of the norm happens, looks like everyone loses last year's Rome points being that the Tennis Calendar has changed this year.

Rank	Name	Points	Moved	Played
1	Nadal, Rafael	11,915	0	21
2	Djokovic, Novak	9,710	0	19
3	Federer, Roger	8,690	0	22
4	Murray, Andy	5,815	0	19
5	Soderling, Robin	5,235	0	24
6	Ferrer, David	4,330	0	22
7	Berdych, Tomas	3,900	0	25
8	Melzer, Jurgen	3,055	0	23
9	Almagro, Nicolas	2,735	+1	27
10	Monfils, Gael	2,690	-1	21